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(No Model.)

SIPTING MAGHINE. No; 400,621.

Patented Apr. 2, .1889.

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(No Model.)

F. Gr. WINKLBR.

SIPTING MACHINE.

Patented Apr. 2. 1889.

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UNITED STATES PATENT OFFICE.

FRIEDRICH GEORG VINKLER, OF ZSCHOPPA, SAX ONY, GERMANY, ASSIGNOR TOROBERT E. LESTER, OF NENV YORK, N. Y.

su-'TING-MACHINE.

SPECIFICATION' forming part of Letterslatent No. 400,621, dated April 2,1889. Application filed November 22, 1888. Serial No. 291,597. (Nomodel.)

referred to, first, of a single-wave generator as distinguished from themultiple-wave generators described in another pending rapplication for apatent, whereby the diameter necessary for the rotating structure isdiminishedand the size of the machine as a whole is .correspondinglyreduced; secondly, of a deflecting-grate composed of acylindricallyarranged system of bars, the spaces between which bars areapproximately diagonal relatively to the radii of the rotatingstructure,

and the width of which at the outer surface of the grate doesnot exceedtheir width at the inner surface of the grate; thirdly, of a spiralscraper affixed to the shaft of the rotating Wave-generator andoperating to prevent the collection of flolur-dust or other material inthe annular spaces between the said shaft and the hollow hubs of therotating deflecting-grate.

The accompanying drawings of a flour-bolting machine containingthe-improvements are a rotating cylindrical sieve, B, mounted upon videdwith bearings C5 and C6 at the ends of the machine. Vithin thecylindrical deflecting-grate is a rotating wave-generator, D, which ismounted upon the swift-running 'shaft E, journaled at its opposite ends,respectively, in the bearings e e', and provided with the fast and loosepulleys E and E2 for engaging the belt by which the Wave-generator isrotated. The hollow hub C4 of the rotating deflecting-grate is providedwith the driving-pulley O7. The hollow hub b of the sieve is providedwith the driving-pulley B2. The portions of the shaft E which arecontained within the hollow hubs C3 and C4 are y upon its outer sidewith a radially-projecting Y strip, i. The space between the outerportions of the slat t' and the radially-proj ecting strip c" may befilled up solid, in which case the outer portion of the slat will havethe 'form of the prism i3, (shown in Fig. 3;) or it may'be leftunfilled, in which case it will constitute the recess 4. (Shown'in Fig.3.)

The single-wave generator is composed of two parallel disks, D D',aflixed to acentral shaft, D2, and united to each other by a fanextending longitudinally across the generator from one disk to theother. Like the doublewave generators described in pending application,No. 291,549, filed November 22, 1888, the fans of the single-wavegenerators may be arranged in a great variety of ways. One of the moresimple forms is illustrated in Fig. 2, inwhich, as will be seen, a fanconsisting of a partition, d, extending radially inward from theperiphery of the generator part way to the shaft, and having its inneredge, d', united to orformed in one piece with a sheet of metal, d2, socurved that its cross-section has a scroll shape, as represented in Fig.2, and which has its edge d3 united to the outer edge ofthe radialpartition d.

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The direction of rotation is indicated by the concentrically-curvedarrow (Z5. vAs the fan rotates, the air gathered within thegraduallynarrowing space between the deHecting-grate and sieve and theadvancing eccentrieallycurved surface d of the fan is ejected in aradially-outward direction, as indicated by the group ofradially-arranged outwardly-pointing arrows. The fan may be considereda-s composed of the radial partition d and of the adjoining portion d3of the curved partition. In front of the advancing fan the air iscompressed, and in the rear of the advancing fan a partial vacuum isestablished. A certain quantity of air is ejected radially from thegenerator through the detlecting-grate and the portion of the sievebetween a line radially opposite the apex of the fan and a parallel lineat a distance of, say, forty-five degrees therefrom, more or less. Aquantity of air equal to that thus ejected is at the same time admittedthrough the remaining three-quarters of the sieve and through thedeflectinggrate into the generator, as indicated by the inwardly-pointedarrows. It will therefore be seen that the rotation of the fanpropagates around the entire sieve a single wave coinposed of vibrationsor outward currents of air of high pressure ejected through acomparatively small portion of the sieve and inward currents of lowpressure which concurrently flow inward through a relatively largeportion of the sieve.

By means of deiectingbars the outward currents are deflected radiallytoward the sieve witlrsuihcient force to press the linerA particles ofmaterial operated upon directly through the meshes, while the. coarsermaterials which, having been thrown against the interior of the sieve,may have lodged thereon, are dislodged by the inward currents of air,and are caught upon the outer surfaces of the deflecting grate-bars.

The direction of rotation of the deliectinggrate is preferably oppositethat of the wavegenerator. The particles which, being thus driveninward, catch upon the grate-bars, are immediately thrown outwardlytherefrom toward the sieve and are again thrown inward by the internalpressure of the external air. The inward currents of air thereforeprevent the interior surface of the sieve from becoming clogged byprogressively clearing from obstructions the part of the sieve which isabout to be subjected to the action of the outgoing currents.

The uniform clearance of all portions of the interiorsurface of thesieve is insured by the establishment within the sieve of a continuousair-current in a path concentric with and extending around the greaterportion of the interior surface. The establishment of this concentriccurrent is permitted by the use of the single-wave generator, whichleaves nearly the whole of the interior of the sieve-cylinderunobstructed. It results that, in addition to the radially-inwardpressure of the external air tending to dislodge the bran or coarscrparticles fromthe inner surface of the sieve, there exists anotherimportant factor in effecting the clearing of the sieve-to wit, theinterior concentric air-current, which tends to sweep the bran from theinner surface of the sieve.

It will be perceived that for the successful operation of siftingapparatus of the type herein referred to it is necessary that thereshall be continuously supplied to the interior of the wave-generator thequantity of air required to furnish the outgoing current, and, as theinward current is of comparatively low pressure, a relativelyconsiderable area of the sieve must be devoted to the purpose ofadmitting it; but by the employment of a single wave generator and theresulting larger proportion of the sieve which is thereby left availablefor admitting the inward current of air of low pressure, the diameter ofthe rotating structure can be diminished, and the size of the machine asa whole, therefore, be correspondingly reduced.

The single-wave generator can be rotated more rapidly than a double-wavegenerator of like diameter, and still a sufficient quantity of air besupplied to the interior of the generator to furnish the amount requiredfor the outgoing current. It therefore follows that by the use of asingle-wave generator the machine, as a whole, can be reduced in sizewit-hout impairing its sifting capacity.

l claiml. The combination, with a cylindrical sieve, of a singlerotating wave-generator for continuously propagating a single wave ofair around the entire circumference of said cylindrical sieve, the saidgenerator consisting, essentially, of two parallel disks affixed to acentral shaft and of a fan extending inwardly from one side of theperiphery of the generator, and extending longitudinally across thegenerator from one of said disks to the other.

2. In combination with a cylindrical sieve and means for establishingoutward and inward currents of air through said sieve, a hollowcylindrical detlecting-grate composed of a system of slats inclineddiagonally with relation to the radial lines, which centrally intersectthem, respectively, and shaped in cross section, substantially asdescribed, whereby the widths of the outer ends of the spaces betweenthe slats are prevented from exceeding-the widths of the inner ends ofthe said spaces.

3. The combination, as herein set forth, of the hollow hubs C3 and C4,of the cylindrical defiecting-grate and the spiral blades e2 and c3,affixed to the portion of the fan-shaft E IOO IIO

which is surrounded by the said hubs, re-

spectively.

FRIEDRICH GEORG WINKLER.

\Vitnesses:

J. I-I. WHITELEGGE, A. M. JONES.

